Diana Walker, the photojournalist who captured the now-iconic scene of Clinton as secretary of State working aboard a C-17 and scrolling a smartphone, is releasing a book of Hillary Clinton photos in October. Walker was Time magazine’s White House photographer for 20 years.

Hillary Rodham Clinton uses this iconic image from her days as secretary of State as the background picture on her Twitter account. (Photo by Diana Walker)

Publisher Simon & Schuster says Hillary: The Photographs of Diana Walker will include behind-the-scenes photos from Clinton’s time as first lady, senator from New York, 2008 presidential candidate and secretary of State. There will be more than 150 high-resolution images in the book, both in color and black-and-white.

From the book’s description:

“As a photographer for Time magazine, she has had unprecedented access to Hillary’s life backstage, capturing the range of Hillary’s emotions and experiences and the many layers of her character. The photos she took at this time are a unique archive of images that paint a revealing and remarkable portrait.”

Walker first photographed Clinton — who says she’s thinking about running for president again in 2016 — in 1976, when Clinton worked at the Rose Law Firm in Arkansas. Her Clinton photos began in earnest in 1993, when Bill Clinton was president.